Hoisting-machine



(No Model.)

J. M. HOWARD.

HOISTING MACHINE.

No. 543,936. Patented Aug. 6, 1895.

flwezz for UNITED STATES PATENT EEIQ JOHN M. HOWARD, OF CHICAGO, ILLINOIS.

HOlSTlNG-MACHINE.

SPECIFICATION forming part of Letters Patent No. 543,936, dated. August 6, 1895.

Application filed June 18, 1894.

To 00% whom it may concern.-

Be it known that I, JOHN MARTIN HOWARD, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Hoisting-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

The object of myimprovement is to provide in hoisting-engines used for elevating passengers and freight means whereby, when from any cause the car or platform becomes obstructed in its descent, the driving-belts will be so shifted as to stop the rotation of the winding-drum.

In the drawings, Figure l is a plan, Fig. 2 is a side View, and Fig. 3 illustrates a detail.

it is a driving-shaft, having thereon fast pulleyf and loose pulleys g g. This shafth is geared with shaft 41: at right angles thereto by means of a worm e on shaft h, meshing with a worm-wheel j on shaft-cc. On. this shaft at is fixed the drum 2,.on which is wound the rope t, connectedat its lower end to the car it. The shaft it has projecting from it at one end a guide-pin 76.

a is a cap into which the pin is projects, and is fastened to the casing 00 inclosing the gearing. Between the cap and inclosed thereby 'and bearing against the washers dis a spring a. Fast on the shaft h is a peripherallygrooved collar k, and into the groove extend pins on the forked arm of a bell-crank lever Z. The other arm of this lever is engaged by the end of an arm m on an upright shaft m. This shaft at its upper end is provided with a laterally-projecting fork n, which" engages a peripheral groove in a collar 19 splined on the shaft 00'. The shaft m is journaled in a bearing supported by a projection 0 from the casing 00. The collar 1) is formed with fingers p, having teeth on their ends forming one member of a clutch and adapted to engage corresponding depressions (forming the other member of the clutch) in the face of a sprocketwheel q loosely mounted on the shaft 0:. Fast on a shaft 00' parallel with shaft on is a sprocket-wheel a connected withv sprocketwheel (1 by a chain 6''. Fast on the shaftm is a pinion f meshing with a rack e, provided at one end with suitable devices y for shift- Serial No. 515,074. (No model.)

ing the driving-belts. The devices shown in the drawings for shifting the belts are those fully shown and described in the patent granted George 0. Howard, dated August 18, 1868, No. 81,170.

The operation is as follows: In the ordinary operation, when the car or other load is lowering, the weight of the car. acting through the winding-drum z, shaft 01:, worm-wheelj, and worm 6, will produceathrustin the shaft h, so as to shift this shaft and all of the parts thereon toward the left, Fig. 1,and compress the spring a. The parts will then be in the positions shown in Fig. 1. In case the carin its descent meets with an obstruction, such removed and the spring 19 will then expand, as in Fig. 3, and the shaft h will be shifted toward the right from the position shown in Fig. 1. This movement of the shaft h, through collar k, bell-crank lever e, arm m, shaft m, and collar 1), with fingers 19, will connect the sprocket-Wheel q with the shaft 00. The motionof the shaft 00' will thus be conveyed to the sprocket-wheel q and through the pinion f to the rack e, whereby the belts will be shifted and the rotation of the winding-drum stopped. 1

In the drawings is shown means for automatically stopping the rotation of the winding-drum when the car has reached thelimits of its travel in either direction. These means are well known and form no part of the present invention.

In the ordinary operation of the elevator the belts are shifted by means of the ordinary controller-rope s passing around pulley s on shaft 00". When the shaft h is shifted by the spring I), the pulleysfand g 9 will be shifted in the direction that the belts are. This movement of the pulleys, however, will be very slight as compared with that of the belts.

What I claim as my invention, and desire to secure by Letters Patent,'is-

1. The combination with the shafth carrying fast and loose pulleys f, g, g, and belt shifting devices, of the shaft at, drum 2 thereon, a rope wound on said drum and carrying a load, gearing connecting shafts h, and 00', the sprocket wheel 1, aclutch adapted to connect sprocket wheel q with shaft w, connecas o in Fig. 2, the weight of the car will be tions whereby or between sprocket wheel q and the belt shifting devices, and means whereby the clutch is operated to connect the sprocket wheel q with the shaft m and shift the belt shifting devices to stop the Winding drum when the load meets with an obstruction in its descent, substantially as described.

2. The combination with the shaft 71 carrying fast and loose pulleys f, g, g, and belt shifting devices of the shaft 0c, drum zthereon, a rope Wound on said drum and carrying a load, gearing connecting shafts h and w, collar k on shaft h, lever Z engaging collar 70, shaft m connected to lever l, sprocket wheel g connected to shaft m, a clutch adapted to I 5 connect sprocket wheel q with shaft or, means whereby the clutch is operated to connect sprocket wheel q with shaft as when the load meets with an obstruction in its descent, and connections between sprocket wheel 1 and the 20 belt shifting devices, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

' JOHN M. HOWARD. Witnesses:

. GEO. W. HAYS,

SAMUEL ARTHUR. 

